Unusual Oviposition on the Body of Conspecifics by Phytophagous Heteropterans

Oviposição Incomum no Corpo de Indivíduos Coespecíficos por Heterópteros Fitófagos

a22v30n3

SCIENTIFIC NOTE

Unusual Oviposition on the Body of Conspecifics by Phytophagous Heteropterans

ANTÔNIO R. PANIZZI¹ AND CLAUDIA H. SANTOS²

¹ Embrapa Soja, Caixa postal 231, 86001-970, Londrina, PR

2Depto. de Zoologia, Universidade Federal do Paraná, Caixa postal 19020, 81531-990, Curitiba, PR

Oviposição Incomum no Corpo de Indivíduos Coespecíficos por Heterópteros Fitófagos

RESUMO - Durante os meses de março de 2000 e fevereiro-março de 2001, observou-se o comportamento de oviposição sobre o corpo de indivíduos da mesma espécie pelo pentatomídeo Euschistus heros (F.) e pelo alidídeo Neomegalotomus parvus (West.). Esse comportamento, incomum para as espécies, foi observado durante a manutenção de colônias dos percevejos em laboratório. Aparentemente, trata-se do primeiro registro de oviposição sobre indivíduos da mesma espécie por essas duas espécies de percevejos em laboratório.

PALAVRAS-CHAVE: Insecta, Heteroptera, Pentatomidae, comportamento de oviposição, co-específicos.

ABSTRACT - During March 2000 and February-March 2001, the oviposition behavior on the body of conspecifics by the pentatomid Euschistus heros (F.) and by the alydid Neomegalotomus parvus (West.) was studied. This behavior, uncommon for the species, was observed while maintaining rearing colonies in the laboratory. Apparently, this is the first record of oviposition on conspecifics by these two species of bugs in the laboratory.

KEY WORDS: Insecta, Heteroptera, Pentatomidae, oviposition behavior, conspecifics.

Oviposition on the body of individuals of the same species (conspecifics) is a relatively rare event among Heteroptera. In spite of many records for carnivorous heteropterans, such as some giant waterbugs (Belostomatidae), whose females lay eggs on the back of the males (e.g., Zeh & Smith 1985, Ichikawa 1989, Smith 1997), little has been reported regarding this behavior for phytophagous heteropterans. To our knowledge, the only two species where eggs are laid on conspecifics by phytophagous heteropterans are: Phyllomorpha laciniata Vill. (Coreidae), a European species (Bolivar 1894), and Plunentis porosus Stål (Coreidae), a South American species (Costa Lima 1940). In the first case, females oviposit on the dorsal surface of both males and females, gluing a variable number of eggs (1-15) (Kaitala 1996). In the second case, females lay their eggs on the ventral side of the abdomen of males (Costa Lima 1940).

During March 2000 and February-March 2001, while maintaining a colony of the neotropical brown stink bug Euschistus heros (F.) and the alydid Neomegalotomus parvus (West.) in the laboratory, we observed oviposition by both species on conspecifics. For E. heros (Fig. 1), this unusual oviposition behavior was observed on eight occasions (Table 1). The number of eggs laid on the back of conspecifics varied from one to nine. In 100% of the cases, the eggs were laid on the back of females. In only one case did nymphs emerge from eggs still glued onto the back of the female; eggs laid on remaining females detached on the oviposition day or one to three days later.

N. parvus oviposition on conspecifics (Fig. 2) was observed on seven occasions. Females laid eggs singly, one egg on each individual, in all cases on females. The place of oviposition was variable, including head, thorax, abdomen, and leg (Table 1). Three times the nymphs emerged from eggs still glued to the bugs. In the remaining cases, the eggs detached from the insect bodies one to two days after oviposition.

This behavior of ovipositing on conspecifics by E. heros and N. parvus was never observed in the field, and may be an artifact due to crowded population of bugs in rearing cages in the laboratory. Whereas such egg laying is usual in P. laciniata, it is not yet been shown to be usual in P. porosus, although it may be, and it is not usual in E. heros and N. parvus. Nevertheless, it is a curious behavior, and may reveal a tendency of these two species to behave like the two coreid species referred to above.The fact that in all cases females laid eggs on conspecific females and never on males, deserves further investigation.

Acknowledgments

We thank C. W. Schaefer and F. Moscardi for revising an early draft of this note. This is a contribution of Embrapa Soja number 01/2001, published with the approval of the Technical Director.

Literature Cited

Received 15/02/01. Accepted 21/05/01.

• Bolivar, J. 1894. Observations sur la Phyllomorpha Feuille J. Natur. 24: 43.
• Costa Lima, A.M. 1940. Insetos do Brasil. Hemípteros. Escola Nacional de Agronomia, Rio de Janeiro, Série Didática N⁰ 3, 2⁰ tomo, Capítulo XXII, 351 p.
• Ichikawa, N. 1989. Breeding strategy of the male brooding water bug Diplonychus major Esaki (Heteroptera: Belostomatidae): Is male back space limiting. J. Ethol. 7: 133-140.
• Kaitala, A. 1996. Oviposition on the back of conspecifics: an unusual reproductive tactic in a coreid bug. Oikos 77: 381-389.
• Smith, R.L. 1997. Evolution of paternal care in the giant water bugs (Heteroptera: Belostomatidae), p. 116-144. In J. C. Choe & B. J. Crespi (eds.), The Evolution of Social Behavior in Insects and Arachnids. Cambridge, Cambridge University Press, 541 p.
• Zeh, D.W. & R.L. Smith. 1985. Paternal investment by terrestrial arthropods. Am. Zool. 25: 785-805.

Publication Dates

• Publication in this collection
  17 June 2002
• Date of issue
  Sept 2001

History

• Received
  15 Feb 2001
• Accepted
  21 May 2001