Relatedness within groups is influenced by the mating patterns of founders: the more parents that contribute to a group, the lower the relatedness of their offspring. Xylocopa virginica (Hymenoptera: Apidae) is a facultatively social bee in which low relatedness is influenced by sequential maternity. We investigated whether multiple paternity, which would occur if egg-laying females mate multiple times, might also contribute to low relatedness among female nestmates. We used two approaches to investigate how frequently females mate polyandrously. First, we used visual observations of mating behaviour to estimate mating frequencies and to evaluate evidence for temporal variation in female receptivity to mates. Second, we used a data set of microsatellite genotypes to evaluate evidence for multiple paternity based on inferred proportions of full and half sisters. Based on visual observations, we inferred a female mating frequency of 1.1 (harmonic mean). Females were more receptive early in their first nestmate provisioning phase and less receptive in their second brood provisioning phase. Based on microsatellite genotypes analysed with COLONY software, we inferred that 5–44% of female sibships included maternal half sisters, implying female mating frequencies between 1.13 and 1.41 (harmonic means). Thus, multiple mating contributes to the low group relatedness found in Xylocopa virginica.

The seedcorn maggot, Delia platura (Meigen) (Diptera: Anthomyiidae), is reported as a polyphagous pest species found in numerous crops, including onion, corn, crucifers, and soy. Two morphologically identical genetic lines of D. platura (H- and N-lines) with distinct distribution ranges were recently discovered. Although many biological traits have been described for D. platura, no study to date has been conducted on the life history strategies and reproductive behaviours of its two lines. Using laboratory-reared colonies, this project investigates the effect of group composition (sex ratio and density) on the mating success and preoviposition period of the two D. platura lines. We found a substantial increase in mating success with increasing proportion of males within mating groups for both lines, whereas we found group density had negligible effects. However, the H-line had a lower average mating probability across treatments compared to the N-line. The preoviposition period decreased as the ratio of males to female increased at low density only for the N-line, and the opposite trend was observed at high density for both lines. These results suggest differences between the mating systems of these two lines, thereby highlighting the need for further research into the factors that influence their respective mating systems.

Penetration of topically applied DDT-C14, at dosages varying between 35 and 2900 nanograms, into individual house flies was studied at 2, 6, and 24 hour intervals. The rate of penetration was found to be dose dependent and not exponential even when nanogram quantities of the chemical were used.

Recent studies in the Larentiinae revealed two new occurrences for North America, one apparently indigenous and the other introduced. A third species discussed below has stood in the American lists for over fifty years on the basis of a misdetermination, and should be removed.

Lygris populata L.

The early literature contains many references to this species in North America but it is almost certain that all such records can be attributed to the superficially similar Nearctic species, Lygris propulsata Wlk. During current investigations in the genus Dysstroma, I encountered Alaskan specimens that proved to be genuine Lygris populata. These specimens, in the collections of three different museums where they were misdetermined as, or mixed in with, material of Dysstroma glacialis Hlst., are as follows:

This species is closely related to Triaspis (T.) halidayi Martin, from South Dakota, and Triaspis (T.) kurtogaster Martin, from eastern North America. In all three species the abdominal carapace is relatively strongly longitudinally rugoso-punctate and apically emarginate, and the clypeus is transverse. The new species may be readily distinguished from kurtogaster by its non-reflexed margin of the clypeus and by its less strongly developed marginal lamella of the third abdominal tergite, and may be separated from halidayi by its stronger, coarser, general rugoseness and darker colour.

Two of my colleagues, in years long gone by, have brought back to me from their journeyings specimens of interesting undescribed mayflies that I have placed in the Cornell University collection to arvait for study a more convenient season. Three of these I now describe. The first two are rather unique species of two well-known genera.

For many years the nymph of Somatochlora walshii Scudd. has eluded our pursuit, in spite of the fact that its geographical range, unlike that of most of our Somatochloras, includes practically all of the settled parts of the eastern provinces and it is by no means a rare species in its special habitat–boggy streams and ditches.

Neothelaxes gen.nov., type-species N. viticola sp.nov., as well as N. parthenocissi sp.nov., are described. The host-plant of the two species is Parthenocissus semicordata. The taxonomic position of the aphids is discussed.

Gauze covers placed over the entrance of one air intake louver (1.52 m × 1.52 m, ht. 11.85 m, air passage 3055.8 cu.m/min) on the penthouse of the Research Station, from May until December, during a 3-year period, trapped more than 150 aphid species. In addition a considerable amount of intercepted aphid material was identified to genus only. A total of 31,482 specimens were trapped over the period.

Five species, Rhopalosiphum maidis (Fitch), Rhopalosiphum padi (Linnaeus), Mindarus abietinus Koch, Alhis craccae Linnaeus, and Capitophorus eleagni (del Guercio), predominated in all years. In 1967 and 1968 more than 100 specimens each of Pterocallis alnifoliae (Fitch), Tinocallis ulmifolii Monell, Myzocallis occultus Richards, Prociphilus americanus (Walker), Capitophorus hippophaes (Walker), Hayhurstia atriplicis (Linnaeus), Thuleaphis rumexicolens (Patch), and Myzus persicae (Sulzer) were trapped each year.

Once potential development temperatures were reached there was little correlation between mean temperatures and aphid numbers up until frost.

The earliest interception was 6 May; general dispersal was under way by 6 June and continued until late November, despite preceding October frost.

On September 10, 1868, during one of our regular Monday morning excursions, I captured on a beech tree, a short distance from London, a larva which I judged to belong to the Smerinthian. genus. Its chief peculiarity, to which I wish to call attention, was its power of emitting a singing noise when handled or disturbed. The noise was similar to that produced by that pretty little beetle so common in our gardens, Lema trilineata. This is the only instance of a musical larva that I have met with, nor do I remember to have ever seen any mention in entomological books of a similar case. I should be glad to know, Mr. Editor, if you, or any of your correspondents, have ever noticed this musical power in any larva? or if you can explain the manner in which the noise is produced.

“Fundamental” or “basic” entomological research may be defined as any research that has insects as the organisms under study and that does not have as its immediate objective the eradication or reduction in numbers of these insects. Within the framework of this deliberately broad definition may be included:

(1) Most, but not all, research done by entomologists in universities, closeted away in their “ivory towers” and generally appearing to the public not to care much about what goes on in the rest of the world. The motivation behind this research is the intrinsic curiosity of the scientist towards insects.

The hydrogen-ion concentration of the alimentary canal of insects has been studied by many workers. In their review of this subject, Day and Waterhouse (1953) conclude that the pH of the foregut is often the same as that of the food, that of the midgut varies in different species from 3 to 10, but that of the hindgut rarely varies far from neutrality. Various methods of determining pH and their relative merits have been discussed by Waterhouse (1940). He considers that incorporating pH indicators into the food is the most accurate method with insects that are too small to enable their gut pH to be measured electrometrically.

The Neotropical genus Acanthoscelio Ashmead is revised. We recognize eight species, found from Costa Rica south to Paraguay and southeastern Brazil. Acanthoscelio americanus Ashmead (Brazil) and A. flavipes Ashmead (Costa Rica, Panama, Venezuela, and Trinidad) are redescribed, and six new species are described: A. acutussp.nov. (Costa Rica, Colombia, Venezuela, Trinidad, Ecuador, Peru, and Brazil), A. latenssp.nov. (Ecuador), A. nimbosussp.nov. (Colombia, Ecuador, Peru, Brazil, and Bolivia), A. prolatussp.nov. (Colombia and Ecuador), A. punctatussp.nov. (Costa Rica, Panama, Colombia, and Ecuador), and A. radiatussp.nov. (Colombia, Ecuador, Peru, Brazil, and French Guiana). A key to species is provided.