Seed-feeding beetles of the weevil tribe Mecysolobini (Insecta: Coleoptera: Curculionidae) developing in seeds of trees in the Dipterocarpaceae

Species comprising two monophyletic groups of Alcidodes sensu lato (crassus group and dipterocarpi group) feed on fruits of the ecologically and economically important tropical timber family Dipterocarpaceae. Fifteen Alcidodes species are newly described from several thousand specimens of seed-feeding beetles reared from south-east Asian dipterocarp hosts (Dipterocarpoidae) and four other species are revised. Morphological keys are provided for identifying these 19 taxa. Weevil associations are provided for 70 species of Dipterocarpaceae in five genera (16 Dipterocarpus spp., four Dryobalanops spp., six Hopea spp., 39 Shorea spp. and five Vatica spp.). These records relate primarily to specimens reared from seeds in Borneo and in Peninsular Malaysia, but all known previous host records are also included (from India, Andaman Islands, Thailand, Laos, Vietnam and the Philippines) and assessed. These validated and documented host associations refute general assertions that (1) seed-eating beetles are host-specific in the tropics and (2) seed-eating beetles found on dipterocarp hosts are broad generalists across species in several genera of mast-fruiting Dipterocarpaceae. Most Alcidodes species exploit seeds from several dipterocarp species. Some Alcidodes species occur across broad geographic regions with several host species from a dipterocarp genus, other species have been found only on Bornean Hopea or Dipterocarpus species. Others, such as the two previously undescribed species feeding on Vatica species, may be restricted to separate sections of the host genus. Within an extensively sampled and diverse interspecific mast-fruiting dipterocarp community, no Alcidodes species was observed to feed on sympatric species across genera within the Dipterocarpaceae. Additional host records and specimens of Alcidodes spp. throughout the range of the Dipterocarpaceae in south and southeast Asia are required to further define these clades and the tribe Mecysolobini in general as well as to resolve the complex host associations and distributions documented.     

Intraspecific larval aggression in two species of Hyperini (Coleoptera: Curculionidae)

Two unusual types of behaviour (wandering and intraspecific aggressive behaviour) have been observed when rearing larvae of two species of the tribe Hyperini. Wandering of Hypera postica in search for food was observed in L1, L2 and L3 larvae, as well as in young L4 larvae. L1 larvae also disperse in response to crowding. Wandering of L2 to young L4 instars was a response to food shortage. Wandering of late L4 larva (‘prepupa’) occurs because of searching for a place to spin the cocoon and pupate. Encounters between the larvae may result in agonistic behaviour, and some larvae may die as a consequence of fighting. This aggression increases with food limitation. Agonistic intraspecific behaviour has not been described to date in weevil’s larvae and it probably may not occur under natural conditions when there is a plenty of food and larval densities are decreased by pathogens or parasitoids.     

Mating behaviour of Staminodeus vectoris (Coleoptera: Curculionidae), and the value of systematics in behavioural studies

The mating behaviour of Staminodeus vectoris Franz (Curculionidae: Curculioninae: Derelomini) is described and discussed in light of a phylogeny of Staminodeus Franz. At La Selva, Costa Rica, S. vectoris is associated with the staminodes of the inflorescences of Asplundia uncinata Harling and several other species of Cyclanthaceae. The males have a row of 6–10 teeth along the margin of the protibia, whereas the females have a small, curved spine on the frons. The adults arrive in numbers at the inflorescences during the pistillate phase of the anthesis of A. uncinata, feeding on the staminodes. Eventually, a female detaches a staminode with her mandibles, falls to the ground, and transports it to the site of oviposition in the leaf litter. First, she crawls underneath the staminode, then moves it posteriorly with her legs, and finally returns to its distal end before repeating the process. The female turns on her back and maintains her original position during the movement of the staminode, using her frontal spine as a point of resistance against the substrate. Meanwhile, a male associates with the staminode. The males fight with their prothoracic legs, executing fast blows until their protibial teeth cling and dislodge competitors from the staminode. The positive and negative allometries of the lengths of the male protibia and female spine, are consistent with their functions in the contexts of sexual and natural selection, respectively. The phylogeny of all seven species of Staminodeus hypothesises that female transporting behaviour evolved before male fighting behaviour.     

Notes on American Sitona (Coleoptera: Curculionidae), with three new species

Historical notes extracted from a taxonomic revision of American representatives of Sitona Germar are presented. Described as new to science are Sitona alpinensis (Utah to Northwest Territories), bryanti (Arizona), and oregonensis (Oregon to Washington).     

Observations on the developmental biology of Cicindela arenicola Rumpp (Coleoptera: Cicindelidae)

Cicindela arenicola Rumpp is being considered for threatened and endangered status by the U.S. Fish and Wildlife Service. Little is known about the developmental biology of this species. Adults of C. arenicola were active from April through late June and late August through early November, but generally they were not on the surface when temperatures were below 19 C or above 45 C, or when conditions were windy, cloudy, or rainy. Mating and egg-laying occurred only during the spring. Five size classes (1-,2-,3-,4-, and 5-mm diameters) of larval burrow openings were observed. Burrows of 5 mm had a mean depth of 42.23 ± 8.81 cm (1 S.D.). Larvae of C. arenicola were active from April through June and late September through mid-November. Developmental times and larval size were affected by food supplementation. Nearly all food-supplemented, 1-mm, first instars molted to larger second instars of3-mm diameter. Most nonsupplemented larvae spent several months as 2-mm second instars before growing to 3 mm in diameter. Food-supplemented larvae reached the third instar in approximately 13 months, while nonsupplemented larvae took slightly over two years to reach this stage. Development from egg to adult was estimated at two years for food-supplemented larvae and three and one-half to four years for nonsupplemented larvae. Cattle had a significant effect on larval mortality. A high percentage (76-80%) of larval C. arenicola that were stepped on by cattle never reopened their burrows. Only 14% of undisturbed larvae never reopened their burrows. Approximately 15% of 150 larvae marked in 1988 reopened burrows in 1989.     

New Notiodes semiaquatic weevil (Curculionidae) from sporocarps of Marsilea mollis (Marsileaceae) in southern Arizona, USA

A new species from the semiaquatic weevil genus, Notiodes sporocarpicus, which develops and pupates in the sporocarps of the water fern Marsilea mollis B.L. Rob. & Fernald, is described from cattle tanks in southeastern Arizona. This new species can be separated readily from the majority of the known species by its nearly straight rostrum, with its distinctive dorsally swollen base and attenuated apex. Its elongate and slender body will separate N. sporocarpicus from most species in the genus except N. aeratus, which lacks the characters above. The Texas species N. celatus resembles the new species but has strongly developed suberect curved setae that are not present in N. sporocarpicus. Included are habitus photos and line drawings of the male and female genitalia of the new species.     

Revision of Indo-Pakistan Parisomias Faust (Coleoptera,Curculionidae) with some notes on Leptomias Faust

Summary

Mandibles and maxillae of Australonuphis teres (family Onuphidae) continue to grow throughout life without replacement. Mandibles are solid structures that grow by external depositions, leaving a series of growth rings. Maxillae are hollow without any growth rings. New teeth are added to a maxilla by the division of its most distal tooth. Overall growth of the maxillae is thought to occur from the inner epidermal layer of the cavity. The same mode of growth is expected in all extant Eunicoidea with exception of Dorvilleidae, where maxillae are periodically replaced.     

Weevil (Coleoptera: Curculionoidea) seed-predators of Syzygium and Eugenia spp. (Myrtaceae), with description of the Alcidodes expansitarsis species group (Coleoptera: Curculionidae: Molytinae: Mecysolobini)

The weevils known to develop in Syzygium and Eugenia (Myrtaceae) fruit are reviewed. These weevils belong to the genera Curculio, Alcidodes, Acythopeus, Apotomorhinus (Curculionidae: Curculioninae, Molytinae and (the last two) Baridinae respectively) and Sitophilus (Dryophthoridae) in the Old World, and Atractomerus (Curculionidae: Anthonominae) in the Neotropics; two undescribed baridine species (one in Australia and the other in the USA) are also known to feed on the fruits, and the Omophorine Teleuropus (Curculionidae: Molytinae) has been found associated with them. Particular attention is paid to species of Alcidodes from aseasonal dipterocarp-dominated forests in South-East Asia. Two Bornean species (Alcidodes janetae sp. n. and A. eugeniophilus sp. n.) are the first of their genus to be reared from the fruit of Syzygium or Eugenia. These species, plus two other (A. expansitarsis sp. n. from Assam, Myanmar, Cambodia and Laos, and A. gymnasticus sp. n. from Malaysia) belong to a previously undescribed species group of Alcidodes; all four species are described and keyed.     

Bionomics,behaviour and immature stages of Pelecotoma fennica (Paykull) (Coleoptera: Rhipiphoridae)

Ptilinus fuscus (Anobiidae) was confirmed as the host species of Pelecotoma fennica (Rhipiphoridae, Pelecotominae). Females of Pelecotoma oviposit into the wood infested by the host larvae. First-instar larvae are elongate, unsclerotized, very different from the triungulinid larvae known in other rhipiphorids. They search actively for the host larvae in the wood; no phoresy is involved in the life cycle. The first-instar larvae temporarily paralyse the host larva and enter its body, overwintering (some perhaps more than once) as an endoparasite. In the spring of the year of emergence, the endoparasite engorges enormously (without moulting) and develops a special sclerotized caudal structure which is then used for perforation of the host's integument. The larva undergoes a further four ectoparasitic instars. The fifth (i.e. fourth ectoparasitic) instar differs considerably from the preceding three, and is capable of boring through the wood to prepare the emergence gallery for the adult. Pupation occurs in the wood. The rate of parasitization may locally far exceed 50%. Superparasitization by the first-instar larvae is possible, but usually only 1 larva survives to the ectoparasitic stage. Larval morphology of Pelecotoma is described and illustrated. Additional data on bionomics and larval morphology are also presented for the genus Metoecus (Rhipiphorinae). Comparing the biology and larval morphology of Pelecotoma with other Rhipiphoridae, it is assumed that ancestral rhipiphorids may have been xylophilous Tenebrionoidea with predaceous or omnivorous larvae, and that the ‘triungulinid’ larvae and phoretic habits may not belong to the groundplan of the family Rhipiphoridae. The widespread opinion considering Rhipiphoridae closely related to the family Mordellidae is questioned.     

Description of new species of Miloderes Casey, with comments on other species of the genus (Coleoptera: Curculionidae)

Miloderes allredi, from Utah, and M. tingi, from California, are described as new to science.     

Biology of Lissoderes Champion (Coleoptera,Curculionidae) in Cecropia saplings inhabited by Azteca ants

This paper provides an account of the biology of Lissoderes (Coleoptera, Curculionidae, Conoderinae) focusing on L. pusillus Hespenheide and L. subnudus Champion. The eggs, larvae, and pupae live inside the hollow stems of Cecropia saplings. Adult weevils chew through the stem and deposit eggs on the inner surface of the internode. The larvae feed on the parenchyma lining the hollow internodes and pupate inside the internode. Emerging adults chew their way out of the stem. Two hymenopteran parasitoids were reared from larvae and prepupae of L. pusillus: Neocatolaccus sp. (Pteromalidae) and Heterospilus sp. (Braconidae). Menozziola sp. (Diptera, Phoridae) and Conoaxima sp. (Hymenoptera, Eurytomidae) were observed parasitizing Azteca queens. Parasitism by these species may explain part of the high mortality observed in colonizing Azteca queens. Direct competition with L. pusillus and L. subnudus appears not to be a major cause of queen mortality, although possible indirect effects of the weevils remain unknown.     

Observations on the heather beetle Lochmaea suturalis (Thomson) (Coleoptera,Chrysomelidae) and its parasitoids

A small population of the heather beetle Lochmaea suturalis (Thomson) in southern England was found to be parasitized by Asecodes mento (Hymenoptera, Eulophidae) and by Degeeria collaris (Diptera, Tachinidae). In recent years outbreaks of L. suturalis in The Netherlands have resulted in alterations of vegetational patterns and this has caused concern. It is suggested that the possibility of biological control of the beetle by A. mento should be investigated.     

Radiation in the halophytic coenoses of the Peri-Tethys: taxonomy and biogeography of the genus Ita (Coleoptera: Curculionidae)

The weevil genus Ita Tournier, 1878 Tournier, H. 1878. Sur deux genres nouveaux de Curculionides. Ann Soc Entomol Belg (C R)., 21: XVIII–XIX.  [Google Scholar] is revised, its phylogeny inferred and its historical biogeography discussed. Its nomenclatural history is detailed and its taxonomic placement within the Curculionidae is examined; the genus is ascribed to the subfamily Curculioninae, tribe Itini. The type specimens of all the described names referable to this genus were examined and lectotypes designated. Ten new species are described. The synonymy Xeronoma Iablokov-Khnzorian, 1964 Iablokov-Khnzorian, SM. 1964. New genera and species of Coleoptera from Transcaucasus and middle Asia. Zool Sb Zool Inst Akad Nauk Armyanskoi SSR, 13: 151–186.  [Google Scholar] = Ita Tournier, 1878 Tournier, H. 1878. Sur deux genres nouveaux de Curculionides. Ann Soc Entomol Belg (C R)., 21: XVIII–XIX.  [Google Scholar] syn. nov. is proposed. The natural history is detailed: all the species for which data are available live in halophytic habitats and are associated with the former family Chenopodiaceae. Inference on phylogeny and hypotheses on historical biogeography are proposed: the genus has probably differentiated not later than the upper Miocene along the south-eastern coasts of the Paratethys; a subsequent radiation occurred as a consequence of the tectonic evolution of the region and through events of dispersion and dispersal.     

Observations on the behaviour of the Cape girdled lizard Cordylus cordylus (Reptilia: Cordylidae)

Cape girdled lizards Cordylus cordylus are social and territorial. Behaviour observed in captivity revealed at least 24 distinct postures and displays. Thermoregulatory behaviour was the most frequent of all behaviours observed (66·7%). Of the social behaviours, aggression was observed most frequently (72·1%). Six behavioural postures are not known to have been described before. This species has no bright colours or contrasting markings to use in displays to conspecifics.     

Mating behaviour in two closely related sympatric species of Philonthus (Coleoptera: Staphylinidae)

Summary

The intra-specific mating behaviour of two closely related sympatric staphylinid beetles, Philonthus cephalotes (Grav.) and P. sordidus (Grav.) is described in detail. Mating is essentially similar in the two species, although differing in the duration of copulation (1·7 min in cephalotes, 44·6 min in sordidus), and consists of four phases (A)-(D); (A) pre-copulatory phase, (1) examination of female abdominal apex by male, (2) examination of male abdominal apex by female, (3) prolonged examination of female by male, (4) mounting by male (5) extrusion of male genitalia; (B) copulatory phase; (C) terminal phase; and (D) post-copulatory phase.

An attempt to test the role of species specific patterns of peg setae, occurring on the genitalia of males, as a tactile signalling system was made by observation of inter-specific interactions between males and females of the two species. Under the trial conditions inter-specific intromission did not occur and behaviour was predominantly aggressive. Evidence suggests that signals during the early stages of an encounter between the sexes of different species are generally sufficient to deter further courtship. In two instances courtship reached a more advanced stage and here the patterns of peg setae on the male genitalia may have come into play, operating as a signalling device.     

Observations on the tube-building behaviour of the marine amphipod Cymadusa filosa Savigny (Crustacea: Ampithoidae)

The study reports on the tube-building behaviour of the corophioidean amphipod, Cymadusa filosa Savigny on two algae, Sargassum binderi Sonder and Ulva lactuca Linnaeus, based on experimental protocols using specimens in aquaria and in petri dishes. Cymadusa filosa was observed to construct open-ended, uniform diameter cylindrical tubes using amphipod silk, to bind together faecal pellets, detritus and fronds of Sargassum binderi or Ulva lactuca. Detailed studies of tube-building behaviour were carried out in petri dishes containing Ulva lactuca, using isolated specimens (5–13 mm in size) of different sexes for a period of one and a half months. Both males and females constructed tubes, and an average of four tubes were built by adults in 15 days. Females with young in the brood pouch did not construct new tubes following juvenile release. Juveniles were observed to build tubes using detritus and faecal material only within hours of being released from the brood pouch. The tubes of juveniles were either built on the walls of their mother's tubes or on an algal mass put together by the mother. There was a highly significant positive correlation between body length and tube length in males and females. There was no significant difference in the rate of tube length increase relative to body size between males and females, between males less than or more than 10 mm, or between females of less than or more than 10 mm. Tube-sharing was also observed between males and females.     

Mating behaviour and sexual selection in the African ball-rolling scarab Khepher platynotus (Bates) (Coleoptera: Scarabaeidae)

Mating behaviour of the ball-rolling dung beetle Kheper platynotus (Bates), adults of which are active in rainy seasons, was studied in southeastern Kenya. Male mating behaviour changed with the progression of the rainy season. In the early season when females made food balls, males attempted forced copulation with wandering and food-ball-making females on dung mounds. As the season progressed, females made brood balls, and males attempted to pair off with such females, as well as attempting forced copulation with wandering and food-ball-making females. A male who paired off with a brood-ball-making female cooperated with the female to make the ball. The male usually copulated after burying the ball (pre-copulatory mate guarding), but sometimes copulated during ball-making. In the latter case the male usually showed post-copulatory mate guarding until ball burial, but sometimes left soon after copulation. In the late season, when available females decreased because of maternal care in the underground nests, males started to make food balls to secure food resources for survival until the next rainy season. Male mate guarding involving ball-making, -rolling and -burying seemed to function to raise paternity confidence, but such assistance seemed to be less beneficial to females. Fights frequently occurred between guarding and intruding males on brood balls. Both residency and relative body sizes of fighters were important asymmetries influencing contest outcome. This seemed to result in not active but passive mate choice by brood-ball-making females.