The clerid beetle,Thanasimus formicarius,is attracted to the pheromone of the ambrosia beetle,Trypodendron lineatum

Summary Sticky traps containing (+)-lineatin, the pheromone of the ambrosia beetle,Trypodendron lineatum, attracted the predatorThanasimus formicarius to about the same extent as traps baited with ipslure, the pheromone blend used for mass-trappingIps typographus. The results indicate thatT. lineatum is an important prey forT. formicarius early in the season before the main prey becomes active. Addition ofexo-brevicomin to ipslure and ethanol and/or -pinene to (+)-lineatin did not significantly influence the catches of the predator.     

The ultrastructure of the spiral notosetae ofNicomache maculata Arwidsson (Polychaeta,Maldanidae)

Summary Scanning- and transmission electron microscopy show that the long, thin notosetae ofNicomache maculata are helical over much of their length, and that their finely feathered appearance is produced by a series of minutely spiny scales. The internal structure varies considerably from one end of the seta to the other. While a helical shape could result from a rotating or asymmetrical secretion-rate gradient across the chaetoblast, we raise the possibility that the spiral represents a warp in the seta following deposition of the setal material.     

The sterols of the khapra beetle, Trogoderma granarium Everts

The khapra beetle, Trogoderma granarium Everts, does not dealkylate and convert dietary C28- or C29-Phytosterols to C27-sterols such as cholesterol. There is, however, an increase in the concentration of cholesterol and campesterol in its tissues relative to the dietary concentrations of these sterols, presumably as a result of selective uptake.     

The sterols of the khapra beetle,Trogoderma granarium everts

Summary The khapra beetle,Trogoderma granarium Everts, does not dealkylate and convert dietary C₂₈- or C₂₉-phytostorols to C _2T sterols such as cholesterol. There is, however, an increase in the concentration of cholesterol and campesterol in its tissues relative to the dietary concentrations of these sterols, presumably as a result of selective uptake.We thank Dr S. R. Dutky of the Insect Physiology Laboratory, Agricultural Research, SEA, USDA, Beltsville, Maryland for providing GC-MS analyses.     

Nervous and behavioral responses to light in colonies of the free-living bryozoan,Selenaria maculata (Busk)

Summary Bursts of electrical impulses which spread throughout the entire colony were recorded from individual zooids ofSelenaria. Strong illumination caused a rapid increase in the frequency of bursts and also caused the colonies to start moving, usually towards the light the recorded electrical activity may act to trigger locomotor behavior.We are grateful to Dr P. Arnold (James Cook University, Townsville) for his assistance in collecting the live material ofS. maculata, to Miss P. L. Cook and Mr P. J. Chimonides (British Museum (Natural History) for their helpful discussions, and to Dr J.P. Thorpe (University of Liverpool) for suggesting the topic. We thank also the Science and Engineering Research Council for financial support (grant No. GR/A71578).     

Effect of the photoperiod on corpus allatum activity in vitro in the beetle,Pterostichus nigrita F

Summary In the carabid beetlePterostichus nigrita reproduction is controlled by photoperiods and the corpus allatum hormone. Corpora allata were incubated in vitro and the release of juvenile hormone was quantified. Short-day conditions induced low activity of the corpora allata; long days, after short-day treatment, stimulate high corpus allatum activity, while long days alone have no effect.     

Influence of larval diapause on pheromone communication in the khapra beetle,Trogoderma granarium everts

Summary InTrogoderma granarium, induction of larval diapause by sub-optimal temperature enhanced the efficiency of pheromone perception by adult males. Such diapause also altered the pattern of pheromone production by females.     

Gene amplification in oocytes of the rove beetle Creophilus maxillosus (Staphylinidae, Coleoptera-Polyphaga).

The extra-DNA body was found, for the first time, in oocytes of an insect with telotrophic ovary. Dispersion of this body is accompanied by an enormous increase of nuclear volume and production of multiple nucleoli. It is suggested that the extra-DNA contains a huge mass of nucleolus organizers.     

Sexual dimorphism in the defensive secretion of a carabid beetle

Summary The defensive secretions of male and femaleOodes americanus display striking qualitative differences. Altogether 13 carboxylic acids were identified in the secretions of the two sexes. Methacrylic, crotonic, and tiglic acids are produced exclusively by the female; the male lacks these unsaturated components, but produces their saturated analogs. 2-Methylbutyric acid is a major component produced by both sexes. Shared components also include hexanoic, (E)-2-hexenoic, benzoic, and (E)-2-octenoic acid, of which the latter two had not previously been reported from carabid beetles.Paper no. 98 in the series Defense Mechanisms of Arthropods; no. 97 is by Smedley et al., J. Lepid. Soc., in press.     

Sexual dimorphism in the defensive secretion of a carabid beetle

The defensive secretions of male and female Oodes americanus display striking qualitative differences. Altogether 13 carboxylic acids were identified in the secretions of the two sexes. Methacrylic, crotonic, and tiglic acids are produced exclusively by the female; the male lacks these unsaturated components, but produces their saturated analogs. 2-Methylbutyric acid is a major component produced by both sexes. Shared components also include hexanoic, (E)-2-hexenoic, benzoic, and (E)-2-octenoic acid, of which the latter two had not previously been reported from carabid beetles.     

Lack of conversion of C29-phytosterols to cholesterol in the khapra beetle,Trogoderma granarium Everts

Summary Metabolic studies in which³H-sitosterol,³H-stigmasterol, and¹⁴C-desmosterol were administered by feeding and injection to the khapra beetle,Trogoderma granarium Everts, provided strong evidence that this insect is unable to dealkylate phytosterols and convert them to cholesterol.     

Tocopheryl acetates from the pupal exocrine secretion of the squash beetle,Epilachna borealis (Coccinellidae)

The oily droplets on the pupal integumental hairs of the squash beetleEpilachna borealis contain a mixture of -, -, -, and -tocopheryl acetates as major constituents. In addition, the secretion contains a number of minor components that appear to be dehydrocongeners of the major components. This is the first report of the occurrence of acetate esters of any tocopherol in nature.This is paper No. 132 in the series Defense Mechanisms of Arthropods; No. 131 is Shi et al., Tetrahedron52 (1996) 6859.     

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.     

The origin of progesterone in the confused flour beetle (Tribolium confusum)

Résumé La progestérone présente dans les tissus deTribolium confusum (coléoptère) tire probablement son origine de la ration alimentaire puisque la concentration de ce stéroïde est du même ordre de grandeur dans l'insecte et dans la ration alimentaire.     

Location of allatostatic centers in the pars lateralis regions of the brain of the Colorado potato beetle

Summary Selective lesions in the pars intercerebralis and pars lateralis areas of the brain of the adult Colorado potato beetle were produced by radiofrequency cautery. The effect of these lesions on the corpus allatum activity, determined by the short-term in vitro radiochemical assay, revealed that gland inhibitory centers are located in the pars lateralis.     

Mitochondrial DNA variation in geographic populations of Colorado potato beetle,Leptinotarsa decemlineata (Coleoptera; Chrysomelidae)

Summary This study demonstrates variability in restriction enzyme cleavage sites of mitochondrial DNA (mtDNA) among four popalations of Colorado potato beetle (CPB). A suite of three enzymes (EcoRI,HpaI,PstI) was sufficient to discriminate among the populations tested. Individuals heteroplasmic for restriction enzyme patterns were found in some populations. Variability in CPB mtDNA should prove useful in efforts to trace the origin and dispersal of the species in North America.     

Identification of both fucosterol and isofucosterol in the siklworm,Bombyx mori

Summary Fucosterol and isofucosterol were identified in the silkworm,Bombyx mori.