Identification of a new predaceous stink bug pheromone and its attractiveness to the eastern yellowjacket

Summary Males ofPodisus fretus (Hemiptera: Pentatomidae) release a long-range attractant pheromone containing linalool (49.0%), (E)-2-hexenal (34.5%), benzyl alcohol (12.0%), nerolidol (2.0%),-terpineol (1.1%), and traces of several other compounds. The eastern yellowjacket,Vespula maculifrons (Hymenoptera: Vespidae), is attracted to artificial pheromones forP. fretus and for the sympatric species,Podisus maculiventris.The authors thank Mr T.J. Henry of the USDA Systematic Entomology Laboratory and Dr J.E. McPherson, Southern Illinois University, for examining the pentatomid species and Dr A.S. Menke, USDA-SEL, for determining the yellowjacket species. We also thank S. Wilzer for technical assistance. Mention of a company name does not imply endorsement by the US Department of Agriculture.     

Biosynthesis of 1-alkenes in the defensive secretions ofTribolium confusum (Tenebrionidae); stereochemical implications

Summary The terminally unsaturated hydrocarbons of the defensive secretion ofTribolium confusum are biosynthesized from fatty acids by oxidative decarboxylation. The process involves an enantiospecific cleavage of the C–H bond of thepro-(S) C(3)–H atom and simultaneous decarboxylation of the acid into an 1-alkene and carbon dioxide via ananti-periplanar transition state geometry (anti-elimination). The stereochemistry of this biotranformation is identical in all respects with the same reaction in higher plants. The mechanism seems to be of general importance for the biosynthesis of many vinylic substructures of natural products from oxygen-containing precursors.     

Aggregated oviposition byChymomyza amoena (Diptera: Drosophilidae)

Summary Aggregated oviposition byChymomyza amoena in Virginia and Michigan has been shown to be due to egg clustering, females attracted to fruits on whichC. amoena females have already oviposited, and to variation in fruit attractiveness. Negative binomialk values support behavioral similarities among females of this rarely seen species in both states. Discovery ofC. amoena in Europe may indicate that this larval overwintering drosophilid has a Holarctic distribution.The research in Virginia during summer 1986, conducted at Mt. Lake Biological Station, was supported by a fellowship from the University of Virginia. Thanks are gratefully extended to all property owners in Virginia and Michigan for allowing me to collect fruits and to Blaine Cole, Director and J.J. Murray, Chairman of the Biology Dept., University of Virginia for research space in 1986 and 1987. R. N. Band constructed the figures. Comments from reviewers have been helpful.     

Pregnanes from defensive glands of a belostomatid bug

The aquatic bugAbedus herberti (Hemiptera: Belostomatidae) secretes a mixture containing four pregnanes (desoxycorticosterone (I), pregnenolone (II), progesterone (III), and 3-hydroxy-pregn-5-en-20-one (IV)) from its cephalic glands. Pregnanes had previously been characterized from the defensive glands of aquatic beetles (Dytiscidae) and shown to be deterrent to fish. It may be specifically under predation pressure from fish thatA. herberti and Dytiscidae evolved their comparable defenses.     

Sexual dimorphism in the lipid fraction of the defensive secretion ofGastrophysa viridula (Coleoptera: Chrysomelidae)

The lipid fraction of the defensive secretion of adultGastrophysa viridula was analyzed by gas-liquid chromatography and gas chromatography-mass spectrometry. Three long chain acetates and two methyl-branched hydrocarbons were identified and their amounts in the secretion of single field-collected and laboratory-reared beetles determined. The composition of the secretion was affected by the sex, reproductive status, and age of the beetle. The ratio of (Z)-11-eicosenyl acetate to (Z)-13-docosenyl acetate ranged from 0.30 to 0.78 in male beetles and from 1.05 to 2.06 in female beetles. The biological significance of this sexual dimorphism is discussed.     

Sound communication inNezara viridula (L.) (Heteroptera: Pentatomidae): Further evidence that signal transmission is substrate-borne

We investigated the sound communication associated with mating inNezara viridula (L.) to clarify conflicting reports on the medium through which acoustic signals are borne. Recordings made from virgin pairs ofN. viridula during precopulatory and compulatory behaviour have revealed that signals transmitted as vibrations through the substrate are a more likely means of communication than signals transmitted by a radiation of sound pressure waves through the air (at least in Australian populations). We present evidence (additional to that already in the literature) that air-borne acoustics are an unlikely mechanism of sexual communication in this species. Specifically, the recorded pulse train patterns showed no consistency or repeatability in relation to different stages of mating behaviour. In contrast, frequency spectrograms of substrate-borne signals reveal repeatable patterns that do correspond with the stage of mating behaviour.     

Plant-sucking bugs can remove the contents of cells without mechanical damage

Summary A mirid and a coreid, feeding on a variety of plant tissues, evacuated the contents of cells up to 3.5 mm from the furthest penetration of their mouthparts. A pectinase occurred in the salivary glands of the mirid and an invertase in those of the coreid, but not vice versa. Cells in the mirid lesions were apparently emptied while the walls retained their shape, whereas coreid lesions showed an immediate inward collapse of cell walls and engorgement of intercellular spaces.14 October 1986Work based on the Biology Department of the University of Papua New Guinea, to which I am grateful for provision of facilities. I am especially grateful to Dr Elaine Brough for arranging the contacts and visits that made field observations and collection of materials possible.     

Glycerol monoethers in the scent gland secretions of the western diamondback rattlesnake (Crotalus atrox; Serpentes,Crotalinae)

Summary 1-O-Monoalkylglycerols with C₁₂ to C₂₀ chains were identified in the scent, gland secretions of the western diamondback rattlesnake (Crotalus atrox). This is the first documentation of these compounds in the skin secretions of a reptile.     

Dilation of nervi corporis allati 2 (NCA 2) — a neurohaemal structure inChrysocoris stolli wolf. (Heteroptera: Pentatomidae)

Summary The NCA 2 is dilated in about the middle of its length. Neurosecretory material is stored in this dilation. It serves as a secondary neurohaemal organ for lateral neurosecretion.     

On the specific attraction of the males of the six-toothed spruce bark beetle,Pityogenes chalcographus (L.) to a mixture of synthetic pheromones of the eight-toothed spruce bark beetle,Ips typographus (L.) (Coleoptera,Scolytidae)

Summary Traps containing a mixture of attractants forIps typographus also caught other species of bark beetles. The numbers ofPityogenes chalcographus, Pityogenes conjunctus, andTrypodendron lineatum were too high to be interpreted as accidental captures. The males of the polygamousP. chalcographus were specifically attracted, indicating that theI. typographus pheromone or one of its components acts as a kairomone and primary attractant for the pioneering males ofP. chalcographus.     

Intergeneric interactions betweenEimeria separata (Apicomplexa) andNippostrongylus brasiliensis (Nematoda) in the rat

Summary Ova production inNippostrongylus brasiliensis infected rats was significantly greater than in rats singly infected with the helminth whenEimeria separata infections were introduced 4, 6 and 11 days postinoculation withN. brasiliensis. Patent periods were unaltered during concurrent infections. These results suggest that the presence ofE. separata affects helminth fecundity but does not increaseN. brasiliensis longevity as has been shown withE. nieschulzi.This study was supported by NIH MB RS Grant RRO8012-8.     

Infection of frog tadpoles (Amphibia) by insect parasitic nematodes (Rhabditida)

Summary Infective stage juveniles ofNeoaplectana carpocapsae (Steinernematidae) andHeterohabditis heliothidis (Heterorhabditidae) were able to penetrate through the alimentary tract of young tadpoles ofHyla regilla (Hylidae) andXenopus laevis (Pipidae) and enter the body cavity. Some infectives ofN. carpocapsae were able to release their symbiotic bacterium,Xenorhabdus nematophilus inside the host and in two cases, the nematodes developed into adult females before they perished. Tadpole mortality was associated with foreign bacteria entering the penetration holes made by the invading nematodes. The infective stage juveniles of both nematodes frequently encountered a host defense reaction upon reaching the tadpole's infective stage juveniles of both nematodes frequently encountered a host defense reaction upon reaching the tadpole's coelom.     

Heat production by balling in the Japanese honeybee,Apis cerana japonica as a defensive behavior against the hornet,Vespa simillima xanthoptera (Hymenoptera: Vespidae)

Summary As an effective counterattack strategy against predacious hornets, especiallyVespa simillima xanthoptera, workers ofApis cerana japonica showed a distinct balling reaction, usually involving 180–300 bees. This produced heat for as long as 20 min, giving rise to temperatures inside the ball higher than 46°C, which is lethal to the hornet but not to the bees.     

The identification of spiroacetals in the volatile secretions of two species of fruit fly (Dacus dorsalis,Dacus curcurbitae)

Summary Aeration extracts from femaleDacus cucurbitae and femaleDacus dorsalis have been shown to contain a variety of 2,8-dialkyl-1, 7-diaxospiro [5.5] undecanes together with N-3-methylbutylacetamide.     

(R)-(Z,E)-9,11-octadecadien-13-olide: An intriguing lactone fromHeliconius pachinus (Lepidoptera)

Summary A fourteen-membered lactone,(R)-(Z,E)-9,11-octadecadien-13-olide, was isolated from extruded abdominal glands of a Neotropical, nymphalid butterfly,Heliconius pachinus (Lepidoptera). This compound was obtained from mature adults of both sexes, but was not detected in young adults or pupae.     

Effects of diapause and host species on some morphometric characters inTrichogramma (Hym.: Trichogrammatidae)

Adult morphology ofTrichogramma is modified by environmental conditions during the preimaginal development. For instance, the low temperatures inducing diapause cause a decrease of the ratio length of longest seta on male flagellum/width of flagellum inT. evanescens. The species of the host also influences numerous body ratios. So, in females, the development of tibiae with regard to wings is more important withScotia ipsilon than withGalleria mellonella. These results confirm the necessity of performing comparative morphological studies on individuals reared in the same conditions.