Nesting behavior of Podium denticulatum Smith (Hymenoptera: Sphecidae)

Abstract

-The nesting behavior of Podium denticulatum Smith was studied on the campus of Ribeirão Preto of the Universidade de São Paulo, SP, Brazil, from September 2003 to August 2005. The wasps established their nests in bamboo canes ranging from 11.4 cm to 26.2 cm in length and from 0.7 cm to 1.8 cm in internal diameter. Podium denticulatum nested almost exclusively in the hot and wet season (September-April), producing at least fi ve generations per year. The cell provisioning was made with adult and nymphal cockroaches (Blattellidae) which were arranged venter-up and with the head inward toward the inner end of the cell. The construction of a temporary closure occurred in cells that took more than one day to be provisioned. The cells provisioned with a greater number of prey were more likely to produce females than males. The nests included 1-6 brood cells separated by mud partitions and arranged in a linear series. The innermost cells of the nests produced females, and the outermost cells produced males. Nests were parasitized by Eulophidae (Melittobia sp.), Chrysididae and Tachinidae.

Nesting habits, alternative nesting strategies and female territoriality of the cockroach-hunting solitary wasp Penepodium luteipenne (Hymenoptera: Sphecidae)

“…The biology of the Podiini is known from short notes on some species (see Pulawski 2011b) and a few more extensive studies (e.g., Williams 1928, Eberhard 1974, Ribeiro and Garófalo 2010. In the present paper the nesting behaviour of Penepodium luteipenne (Fabricius, 1804) is described, including five alternative nesting tactics and a peculiar female territorial behaviour.…”

“…An exception was observed by Ribeiro and Garófalo (2010) who found that P. denticulatum oviposited sometimes before and sometimes after placing its prey in the nest. The behaviour of ovipositing outside the nest may be due to the lack of space inside the nest such that the female cannot assume the characteristic oviposition posture necessary for her to oviposit on a forecoxa of her prey.…”

“…However, some other Podiini have been observed constructing temporary nest closures when nest provisioning is not completed in one day [Trigonopsis cameronii (Kohl, 1902) : Eberhard 1974; Podium denticulatum F. Smith, 1856: Ribeiro and Garófalo 2010]. Penepodium luteipenne leave their nests open even on occasions when provisioning is not completed in one day.…”

“…Oviposition on the first prey item stored in the nest has been observed among most of the Podiini studied to date (Penepodium gorianum: Garcia and Adis 1993; Podium denticulatum: Ribeiro and Garófalo 2010;Podium rufipes: Krombein 1970;and Trigonospis cameronii: Eberhard 1974). Only P. luteipenne, in this study, and the Amazonian P. luteipenne studied by Williams (1928), oviposit on the last hunted prey item.…”

“…gorianum: Garcia and Adis (1993); P. latro : Buys 2006;Podium denticulatum: Camilo et al 1996, Ribeiro andGarófalo 2010;P. luctuosum: Krombein 1967;P.…”