Mating Behavior of Cephalonomia tarsalis (Ashmead) (Hymenoptera: Bethylidae) and the Effect of Female Mating Frequency on Offspring Production

The courtship behavior of Cephalonomia tarsalis, a solitary semiectoparasitoid of Oryzaephilus surinamensis, was investigated in the laboratory. Courtship behavior includes a series of stereotypic movements. Males play the most active role, executing the majority of courtship action, and females respond with relatively limited observable behaviors. Males typically keep antennae still during encounters with females prior to mounting, which may be correlated with recognition of the female's sexual status. After mounting, males display a series of movements on females, such as antennae touching female's antennae, antennae or mouth touching female's head or thorax, and walking around on female, which may serve to stimulate females towards increased receptivity. Females signal receptivity by assuming a stereotypical posture of remaining stationary, with head down, and antennae still in front of the body. The male then inserts his aedeagus and the pair copulates. After an average of 40.4 s of copulation, females signal the end of copulation by waving the antennae and moving away from the copulation site. Males continue copulating for a short time after females start moving but dismount soon thereafter. After dismounting, the two wasps move away from each other immediately, and they typically begin grooming. Neither males nor females exhibit mating preference based on mate's mating status in both choice and no-choice tests. The male is polygynous and the mated female can mate multiple times within the first 3 days after starting oviposition. However, female mating frequency does not affect the production of female progeny.     

Human Sting of Cephalonomia gallicola (Hymenoptera: Bethylidae) in Korea

Hymenoptera stings can cause serious injury to humans. We report the clinical findings of 6 cases of Hymenoptera stings. All patients developed painful erythematous papules at the sting sites and had a past history of parasitoid wasp sting. This is the first clinical report of the parasitoid wasp, Cephalonomia gallicola, causing human stings in Korea.     

中国烟草甲的寄生蜂一新记录种

记述头甲肿腿蜂属1新记录种——盖拉头甲肿腿蜂Cephalonomiagallicola(Ashmead,1887)。标本保存于浙江大学寄生蜂标本室。     

Influence of previous mating experience on future mating success in maleLucilia cuprina (Diptera: Calliphoridae)

Receptive and virginL. cuprina females were placed with a virgin male and an experienced male that had mated between one and five times previously. The experienced males secured significantly more matings than virgin males. Males with previous matings also gained experience in competing with males. Males directed mating attempts at each other, seemingly in the context of intrasexual competition. Experienced males directed more mating attempts at virgin males than vice versa. As their number of previous matings increased, experienced males made the first mating attempt at females more often and directed more mating attempts at females compared with virgin males. Females did not actively discriminate against experienced males, even though the proportion of matings secured on the first attempt by experienced males declined with increasing mating experience. Alternative behavioral explanations are discussed.     

Behavior and Activity Pattern of Cephalonomia stephanoderis (Hymenoptera: Bethylidae) Attacking the Coffee Berry Borer,Hypothenemus hampei (Coleoptera: Scolytidae)

We describe behavioral sequences and daily activities of pre-ovipositing and ovipositing females of Cephalonomia stephanoderis (Hymenoptera: Bethylidae), an ectoparasitoid of the coffee berry borer, Hypothenemus hampei (Coleoptera: Scolytidae). Noticeable behavioral differences among preovipositing and ovipositing females include host examination, host stinging—probing, host feeding, and the oviposition per se. The female of C. stephanoderis feeds primarily on host eggs, but pupae are also exploited, mainly by pre-ovipositing females. After the onset of the oviposition period, C. stephanoderis examines the pupae repeatedly, stings them at frequent intervals, and spends more time feeding than during the pre-oviposition period. Host paralysis is linked both to host feeding and oviposition. It induces irreversible developmental arrest, which presumably allows preservation of the host until subsequent utilization, and contributes to successful offspring development, particularly by reducing host motility. Oviposition consists in a host selection process, a prolonged period of preparation of the potential host, and the egg-laying phase itself. Under our experimental conditions, pre-ovipositing and ovipositing females are active 17% and 36% of the day, respectively. Host handling time averages 6% and 23% in pre-ovipositing and ovipositing females, respectively. All coffee berry borer developmental stages are exploited by C. stephanoderis females, either for host feeding and/or oviposition activities. Such flexible behavior is advantageous given that host availability is limited inside the coffee berries.     

The effect of female mating history on sperm precedence in the two-spot ladybird, Adalia bipunctata (Coleoptera, Coccinellidae)

Effects of two different mating regimes on sperm precedencein the two-spot ladybird, Adalia bipunctata, were studied usingthe polymorphic gene for melanism as a marker for paternity.Virgin nonmelanic females (homozygous recessive) were matedto nonmelanic male(s) and then, after laying fertilized eggs,were mated to a melanic male of known genotype. The resultsafter the two successive single matings showed a highly variabledegree of paternity of the second male. Initial multiple matingwith nonmelanic males did not alter the pattern of paternityafter the subsequent single mating with a melanic male, butit had two other effects: (1) the female showed an increasein rejection behavior, and (2) a longer copulation was requiredfor high success of the melanic male. Additional observationsin which families were reared from beetles collected in copulain the field demonstrated that sperm competition also occursunder natural conditions. The outcome of the competition wasvariable with frequent sperm mixing.     

Morphology and chemistry of Dufour glands in four ectoparasitoids: Cephalonomia tarsalis,C. waterstoni (Hymenoptera: Bethylidae), Anisopteromalus calandrae,and Pteromalus cerealellae (Hymenoptera: Pteromalidae)

The venom apparatus of four hymenopterous parasitoids, including two bethylids, C. tarsalis (Ashmead) and C. waterstoni (Gahan), and two pteromalids, A. calandrae (Howard) and P. cerealellae (Ashmead), were removed and the associated Dufour glands characterized with respect to their external morphology and chemistry. Dufour glands in all four species have a characteristic translucent appearance that apparently results from their lipid content. The stalked Dufour glands of C. tarsalis and C. waterstoni are pear-shaped and have overall lengths of approximately 0.2 and 0.15 mm, respectively. The thin venom glands are bifurcate and insert through a fine duct into the transparent ovoid- to pear-shaped venom reservoir in these bethylids. In A. calandrae and P. cerealellae the Dufour glands are elongated, tubular structures of ca. 0.35 and 0.8 mm in length, respectively, that constrict to a short stalk that empties into the common oviduct. The venom glands in these pteromalids are simple elongated structures that insert into the sac-like venom reservoir through a fine duct. The chemistry of the volatile contents of the Dufour gland in these four species differs considerably. C. tarsalis Dufour glands contain the same hydrocarbon components as found on the cuticle of this species (Ann. Entomol. Soc. Am. 91:101-112 (1998)), and no other chemicals. The Dufour glands of C. waterstoni also contain only hydrocarbons, most of which are the same as the cuticular hydrocarbons (Ann. Entomol. Soc. Am. 85:317-325 (1992)), but in addition the Dufour gland contains ca. 3% of a mixture of 2,17- and 2,19-dimethyl C(23). A. calandrae Dufour gland chemistry is somewhat more complex than that of either of the two bethylids, but like the bethylids, only hydrocarbons are present. The carbon number range is from C(30) to C(39) and consists of a mixture of n-alkanes (C(30)-C(38)); 3-, 5-, 7-, 9-, 11-, 12-, 13-, 14-, 15- and 17-methyl alkanes; 3,7- and 3,11-dimethyl alkanes; 5,9- and 5,17-dimethyl alkanes; 7,11-, 9,13-, 13,17-, 14,18- and 15,19-dimethyl alkanes; 3,7,11- and 3, 9,15-trimethyl alkanes; and 3,7,11,15-tetramethyl alkanes. The cuticular hydrocarbons of this species have not been previously reported, but they are the same as the Dufour gland hydrocarbons. The Dufour glands of P. cerealellae contain both hydrocarbons and two long-chain aldehydes. Most of the hydrocarbons are identical to those found on the cuticle of this species (Ann. Entomol. Soc. Am. 94:152-158 (2001)), but in addition, 5,9-dimethyl C(27), 5,13-, 5,17- and 5,19-dimethyl C(35), 12- and 14-methyl C(36), 12,16- and 13,17-dimethyl C(36), 13-methyl C(37) and 13,17-dimethyl C(37) are present. The two aldehydes detected in glands from P. cerealellae are n-tetracosanal (C(23)CHO) and n-hexacosanal (C(25)CHO).     

Interactions Between Swarming Chironomus annularius (Diptera: Chironomidae) Males: Role of Acoustic Behavior

Males of swarming species of chironomids use their auditory system (Johnston's organs) to recognize a female within swarm and do not respond to male flight tones. However, in some cases the male–male interactions were observed at a high frequency. The role of acoustic behavior in this phenomenon in C. annularius was studied. The results showed that male Johnston's organs were sensitive to male flight tones from a distance of about 1–1.5 cm. The carrier frequencies of these sounds negatively correlated with male body size. Thus we would expect that male–male interactions will occur mainly between large males. Nonetheless, the analysis of caught pairs revealed that in both male–male and female–male interactions small males had an advantage. The ability of males to perceive the male flight tones is discussed with respect to swarming behavior and mating success.     

Quality control of Cotesia flavipes (Cameron) (Hymenoptera: Braconidae) from different Brazilian bio-factories

The goal of this study was to evaluate the quality of Cotesia flavipes from different bio-factories as biological control agents. We evaluated biological characteristics of the parasitoids throughout their lifespan, and measured the body length and width, abdomen width, thorax width and width and length of the right forewing of female and male parasitoids. Our results showed that the number of males and pupal viability were similar among the bio-factories; the number of emerged females was greater in bio-factories I and II; the egg-pupa period and the pupal period were shorter in bio-factory IV; and a greater longevity was found in bio-factories II and III. Sex ratio (at approximately 60% females) was satisfactory (in terms of suitability for release) across all bio-factories. For morphometric measurements, the body, abdomen and wing widths were similar in males; however, thorax width was greater in the males from bio-factory I; bio-factory III produced females with the highest body length; bio-factory I produced females with the greatest abdomen width; bio-factories III and IV produced females with the greatest wing length. Among the bio-factories studied, bio-factory IV produced the best quality C. flavipes, with respect to the greatest number of parasitoids per pupal mass (a mean of 57% more parasitoids) in a satisfactory sex ratio, and with the shortest developmental time, which facilitates faster rearing in the laboratory. Studies such as this, which assess the quality of a mass-produced C. flavipes, are crucial for the continued use of this parasitoid in controlling Diatraea saccharalis in the field.     

Decoy presentations as a means to manipulate the risk of extrapair copulation: an experimental study in a semicolonial raptor, the Montagu's harrier (Circus pygargus)

Mate guarding and frequent copulations are two alternative paternity assurance strategies found in birds. In species with intensecourtship feeding, like raptors, the "frequent copulation"strategy is expected because male food provisioning conflictswith mate guarding. We evaluated experimentally the paternityassurance behavior of a semicolonial raptor, the Montagu'sharrier Circus pygargus, using decoy presentations to simulateterritorial intrusions. Breeding pairs were exposed to maleand female decoys at different periods during the female's reproductive cycle. Agonistic responses to decoys were intra-sexual,and the timing and intensity of male attacks toward male decoyssupported responses related to the risk of extrapair copulation(EPC): Male aggression peaked during the presumed fertile periodand almost disappeared after clutch completion. During thefertile period, copulation rate was significantly higher, andcopulations lasted longer, during male decoy presentations than during controls. Males also spent more time close to the femaleduring male decoy presentations compared to controls, bothduring the early prelaying and fertile periods, but not duringincubation. In the fertile period, males also increased presencetime close to the female in the hour following the removal of the male decoy. Conversely, female decoy presentations hadno significant effect on copulatory behavior or male presencetime. These results showed that the risk of EPC can be experimentallymanipulated by the means of decoy presentations, simulatingmale territorial intrusions, and that male Montagu's harriersincrease their short-term copulation frequency and female surveillancewhen they perceive themselves at an increased EPC risk.     

First record of Alysia alticola Ashmead (Hymenoptera: Braconidae) in the Neotropical region

Alysia alticola Ashmead, 1890, is recorded for the first time in central Argentina, reared from pig carcasses. This is also the first mention of the genus Alysia Latreille, 1804, in Argentina, which represents the southernmost record in the Neotropical region.     

Associative Learning of Color by Males of the Parasitoid Wasp Nasonia vitripennis (Hymenoptera: Pteromalidae)

Males of the parasitoid wasp Nasonia vitripennis showed no innate preference for blue versus yellow or for green versus brown. They learned to associate color with mates, but their ability to do so depended on the color used and the strength of the reward. Specifically, males learned to associate brown or green with a reward of many virgin females. With fewer females, fewer training periods, or mated females as the reward, males still learned a preference for green but not for brown. Males did not learn to associate color with rewards of honey or water. Previous studies of color preference and associative learning in parasitoid wasps have focused almost entirely on females. This is the first demonstration of associative learning in response to visual cues by male parasitoid wasps.     

Gregarious emergence of Macrostomion sumatranum (Hymenoptera: Braconidae; Rogadinae) from the mummified, full-grown larvae of Theretra silhetensis (Lepidoptera: Sphingidae)

Twenty‐six to 160 adults of Macrostomion sumatranum emerged from a mummified full‐grown larva of a sphingid moth, Theretra silhetensis, on taro in Okinawa‐jima, Japan. This is the first host record of M. sumatranum. The sex ratio was female‐biased in a small brood but less so or even male‐biased in a large brood.     

Sperm transfer in the antCarebara vidua F. Smith (Hymenoptera: Formicidae)

Summary Sperm transfer in the myrmicine antCarebara vidua was studied by making histological sections of newly mated queens. Queens are multiply inseminated, and longitudinal sections through the sperm- filled vagina show that the bundle of sperm from each male is enclosed in a layer of accessory gland secretion terminating in a plug of secretion in the female's vaginal orifice. This spermatophore breaks down soon after mating. The huge quantity of sperm packed into the spermatheca (ca. 16 mm³) suggests that the queen lays a large number of eggs in her lifetime, confirmed by the average of 1672 ovarioles in the two ovaries.     

The Race for Females: The Mating System of the Red Mason Bee, Osmia rufa (L.) (Hymenoptera: Megachilidae)

The ecology of a species strongly influences the strategies with which males and females maximize their lifetime reproductive success. When males and females do not invest equally in offspring, the sex with the higher parental investment becomes a rare resource for the other. The spatial and temporal distribution of the limiting sex forms the basis of the mating system. In nest-constructing Aculeata such as the red mason bee, Osmia rufa, females perform intensive brood care, whereas males do not invest in their offspring but instead compete for access to mates. Receptive females of this species are widely distributed and do not assemble at certain places. Therefore, territorial behavior is not an advantageous mating tactic for males, which instead search for females within individual home ranges usually centered around food plants. The unmarked or defended home ranges of different males may completely overlap. Competitive searching leads to a random distribution of matings among males that is largely independent of body size. The mating system of O. rufa can be described as scramble competition polygyny.     

Distribution and Abundance of Mymarid Parasitoids (Hymenoptera: Mymaridae) of Sophonia rufofascia Kuoh and Kuoh (Homoptera: Cicadellidae) in Hawaii

The abundance of mymarid parasitoids attacking the two-spotted leafhopper (Sophonia rufofascia [Kuoh and Kuoh]), a polyphagous pest recently adventive to Hawaii, was monitored using yellow sticky cards deployed in several areas on the islands of Kauai and Hawaii. The yellow cards captured Chaetomymar sp. nr bagicha Narayanan, Subba Rao, & Kaur and Schizophragma bicolor (Dozier), both adventive species, and Polynema sp. Haliday, which is endemic to Hawaii (Hymenoptera: Mymaridae). The former two species were most abundant at all sites. On Kauai, there was a negative correlation between the captures of C. sp. nr bagicha and those of Polynema sp. Throughout the season, the increase in parasitoid numbers generally followed the increase in leafhopper numbers. C. sp. nr. bagicha and S. bicolor showed distinct habitat preferences. Removal of Myrica faya Aiton, an invasive weed that is a highly preferred two-spotted leafhopper host, decreased the overall numbers of captured parasitoids, but led to a twofold increase in the ratio of trapped parasitoids/hosts in weed-free areas.     

Adaptiveness of sex ratio control by the pupal parasitoid Itoplectis naranyae (Hymenoptera: Ichneumonidae) in response to host size

Adaptiveness of sex ratio control by the solitary parasitoid wasp Itoplectis naranyae (Hymenoptera: Ichneumonidae) in response to host size was studied, by examining whether differential effects of host size on the fitness of resulting wasps are to be found between males and females. The offspring sex ratio (male ratio) decreased with increasing host size. Larger hosts yielded larger wasps. Male larvae were less efficient in consuming larger hosts than female larvae. No significant interaction in development time was found between parasitoid sex and host size. Larger female wasps lived longer than smaller females, while longevity of male wasps did not increase with increasing wasp size. Smaller males were able to mate either with small or with large females, while larger males failed to mate with small females. Larger female wasps had a greater number of ovarioles and mature eggs at any one time than smaller females, although the number of eggs produced per host-feeding was not influenced by female wasps. Thus, the differential effect of host size on the fitness of males and females exists in I. naranyae. The basic assumption of the host-size model was therefore satisfied, demonstrating that sex ratio control by I. naranyae in response to host size is adaptive.     

白蜡吉丁肿腿蜂对栗山天牛低龄幼虫的寄生作用

栗山天牛Massicus raddei（Blessig）是我国东北危害栎树的重要害虫。在对其进行生物防治研究中,通过功能反应实验方法探讨了利用寄生蜂白蜡吉丁肿腿蜂Sclerodermus pupariae Yang et Yao对栗山天牛低龄幼虫的寄生作用。结果表明：白蜡吉丁肿腿蜂在取食寄主补充营养的过程中,对栗山天牛1～2龄小幼虫的致死作用随着寄主密度的增加而显著提高,功能反应符合Holling Ⅱ型方程,平均每日最大致死量为0.53头。寄生作用功能反应符合Holling Ⅰ型方程,寻找时间21 d内的寄主密度阈限为4头。当该肿腿蜂密度固定为1头时,对栗山天牛致死作用和寄生作用的寻找效率均随寄主密度的上升而降低。当寄主密度固定不变时,随着寄生蜂密度的增加寄主的死亡数量线性升高,被寄生的寄主数量也上升,但该肿腿蜂对栗山天牛低龄幼虫致死作用和寄生作用的寻找效应均显著下降,表明白蜡吉丁肿腿蜂是防治栗山天牛低龄幼虫的良好天敌。研究结果对于合理评价白蜡吉丁肿腿蜂在生产上的控害能力和制定寄生蜂的林间释放应用技术规程提供了依据。     

Importance of large colony size for successful invasion by Argentine ants (Hymenoptera: Formicidae): Evidence for biotic resistance by native ants

Abstract The Argentine ant, Linepithema humile (Mayr), is a widespread invasive ant species that has been associated with losses of native ant species and other invertebrates from its introduced range. To date, various abiotic conditions have been associated with limitations to the spread of Argentine ants, however, competitive interactions with native ant fauna may also affect the spread of Argentine ants. Here, we experimentally manipulated colony sizes of Argentine ants in the laboratory to assess whether Argentine ants were able to survive and compete for resources with a widespread, dominant native ant, Iridomyrmex‘rufoniger’. The results showed that over 24 h, the proportions of Argentine ants that were alive, at baits, and at sugar water decreased significantly in the presence of Iridomyrmex. In addition, Argentine ant mortality increased over time, however, the proportion of the colony that was dead decreased with the largest colony size. Argentine ants were only able to overcome Iridomyrmex when their colony sizes were 5–10 times greater than those of the native ants. We also conducted trials in which colonies of Argentine ants of varying sizes were introduced to artificial baits occupied by Iridomyrmex in the field. The results showed that larger Argentine ant colonies significantly affected the foraging success of Iridomyrmex after the initial introduction (5 min). However, over the first 20 min, when the Argentine ants were present at the baits, and over the entire 50 min experimental period, the numbers of Iridomyrmex at baits did not differ significantly with the size of the Argentine ant colony. This is the first experimental study to investigate the role of colony size in the invasion biology of Argentine ants in Australia, and the results suggest that Iridomyrmex may reduce the spread of Argentine ants, and that Argentine ants may need to attain large colony sizes in order to survive in the presence of Iridomyrmex. We address the implications of these findings for the invasion success of Argentine ants in Australia, and discuss the ability of Argentine ants to attain large colony sizes in introduced areas.