INVESTIGADORES
COSCARON Maria Del carmen
artículos
Título:
The shield backedbug, Pachycoris stallii. Description of immature stages, effect of maternal care on nymphs, and notes on life history
Autor/es:
WILLIAMS III, L.; COSCARON, MC; DELLAPE, PM; ROANE, TM
Revista:
Journal of Insect Sciences
Editorial:
Entomological Society of America
Referencias:
Año: 2005 vol. 5 p. 1 - 29
ISSN:
1536-2442
Resumen:
The life history of the shield-backed bug, Pachycoris stallii Uhler (Heteroptera: Scutelleridae),
immatures was studied on its host plant, Croton
californicus Muell.-Arg.
(Euphorbiaceae), in Baja California Sur, Mexico. Immature stages are described
and illustrated. Pachycoris
stallii is bi-
or multivoltine and occurs in xeric areas with sandy soil where it is rarely
encountered away from C.
californicus. Nymphs and adults feed on seeds within C. californicus fruit. Bugs oviposit on the underside
of leaves, and females guard their eggs and first-instar nymphs from natural
enemies. Embryonic orientation of prolarvae is nonrandom; each embryo is
oriented with its venter directed toward the ground. This orientation may
facilitate aggregation of first instars. The longitudinal axes of eggs are
always oriented upward at about a 16° angle of deviation from a line
perpendicular to the leaf surface. This is the first recorded observation of
this phenomenon in Pentatomoidea. Experimental removal of females guarding
first instars results in 100% loss of nymphs, and this is attributed to
disruption of the aggregative behavior of nymphs. Maternal guarding appears to
be a net benefit to P. stallii,
despite possible costs to the brooding female.