Adul T -Juvenil E Aliment Ary Relationships in Passalidae (Coleoptera)
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ADULT -JUVENIL E ALIMENT ARY RELATIONSHIPS IN PASSALIDAE (COLEOPTERA) JoRGE E. V ALENZUELA-GONZALEZ Instituto de Ecología. A. C Apartado PP<,tal No. 63 91000 X a lapa. Veracruz y Centro de Investigaciones Ecológicas del Sureste Apartado Postal No. 36 30700 Tapachula. Chiapas MFXICO Folia Entomolrígica A1c\imna No. 85. 25-37 (1992) Rcccivcd fnr puhlic.llion btllJ:Ir\ 2h. ¡qq_• Acn·pt,·d f,ll. puhliL:!Iinll !uil 1..! lli'l2 26 FOLIA ENTOMOL. MEX. 85 (1992) V ALENZUELA: ALIMENTAR Y R ABSTRACT INTROD The reBults reported in this paper show that !luvae of passa.lids are unable to feed directly from wood. Their main BOUree of food is a mixture of adult faeces and powdered wood Parental behaviors in Passalids in fragments produced by adults during galleries excavation. Newly emerged adults are also eggs, 2) excavation of galleries, 3) pu unable to use wood as their souree of food unless they have previously ingest faeces from older several aspects of the biology and beh adults. This fact suggests the existence of a symbiotic relationship with rnicroorganisms for 1932; Gray, 1946; Reyes-Castillo, degradation and/or assimilation of wood in adults. On the other hand, 1 also found that, usually, Schuster, 1985; Reyes-Castillo adult faeces has a higher nitrogen concentration than ingested wood. In larvae faeces, this & phenomenon may also take place but less frequently; besides, increases tend to be considerably Castillo, 1985; Valenzuela-Gonzalez & less than with adults. Differences found between larvae and adults regarding their ability to use 1986a, b). wood for feeding are probably dueto sorne important variations existing in their digestive tracts. The main difference concems the existence, in aduts, of a structure that could be a fennentation The nature of the interactions be chamber; this structure is absent in larvae. The importance of these alimentary relationships, nutrition, has not been well elucidatec in regard to the evolution of social bchavior in passa.lids, is discussed. food for Passalids is a mixture of KEY WORDS: Passalidae, Coleoptera, Parental Behaviors, Subsocial Behavior, Nutrition, during gallery excavation and faeces (1 Xylophagy. Castillo & Halffter, 1984; Valenzuel constantly compressed by adults again RESUMEN lined with this mixture. Los resultados reportados en este trabajo muestran que las larvas de los pasálidos son Ohaus (1900, 1909) was the first t1 incapaces de alimentarse directamente de la madera. Su fuente principal de alimentación es una for their feeding, due an insufficie1 mezcla de excrementos de adultos y fragmentos de madera producidos durante la excavación de las galerías. Los adultos recién emergidos tampoco pueden sobrevivir con una dieta a base xylophagous nutrition. More recently de madera si no tienen la oportunidad de ingerir, previamente, excrementos de otros adultos. have a mandibular force that is far ~ Estos resultados sugieren la existencia de relaciones simbióticas con microorganismos para la Castillo & Jarman, 1981; Jarman & degradación de la madera en los adultos. Se encontró también que los excrementos de los could give sorne support to Ohaus' adultos poseen, generalmente, un mayor contenido de nitrógeno que la madera de que se reported that the larvae's mandibules 1 alimentan. Este mismo fenómeno ocurre en los excrementos de las larvas, pero con menor frecuencia que en los adultos; por otra parte, dichos incrementos son considerablemente mayores he claimed that, concerning their fe1 en el caso de los adultos que en el de las larvas. Estas diferencias entre larvas y adultos, adults. Pearse et al (1936) and ( concernientes a su capacidad de poder aprovechar la madera cpmo fuente de alimentación, observations, but their results are inc1 probablemente sean originadas por las variaciones existentes en sus tubos digestivos. La of adults in larvae nutrition. Finally, diferencia principal radica en la presencia de una estructura, que probablemente funciona como Odum (1969) showed the importance una cámara de fennentación, en el intestino de los adultos; dicha estructura no existe en las larvas. Por último, se discuten algunos aspectos de la importancia que la xilofagia puede haber tenido en la evolución del comportamiento social en estos insectos. Concerning the participation of syn ofthese insects, Lewis (1926) and Pea PAlABRAS CIA VE: Passulidue, Colcoptcrn, Comportamientos Parentales, Comportamiento for cellulotic protozoires in the gut Subsocial, Alimentación, Xilofagia. However, jt is well known that bacteri intestines of Passalids, but it is unkr participation in the nutrition of thes Heymons, 1934; Patterson, 1937; Lh -fOL. MEX. 85 (1992) VALENZUELA: ALIMENTARY RELATIONSHIPS IN PASSALIDAE 27 ~BSTRACT INTRODUCTION " that larvae of passalids are unable to feed directly ia a mixture of adult faeces and powdered wood Parental behaviors in Passalids include: 1) care and protection of the lcrica cxcavation. Newly emerged adults are also eggs, 2) excavation of galleries, 3) pupal cell building and 4) feeding. (For unlesa thcy havc previously ingest faeces from older several aspects of the biology and behavior of the group, see: Miller, 1931, r a aymbiotic rclationship with microorganisms for 1932; Gray, 1946; Reyes-Castillo, 1970; Schuster, 1975; Schuster & adults. On the other hand, 1 also found that, usually, llration than ingested wood. In larvae faeces, this Schuster, 1985; Reyes-Castillo & Halffter, 1984; Jarman & Reyes rcquently; besides, incrcases tend to be considerably Castillo,1985; Valenzuela-Gonzalez & Castillo, 1984; Valenzuela-González, :ween larvae and adults regarding their ability to use 1986a, b). important variations existing in their digestive tracts. , in aduts, of a structurc that could be a fennentation The nature of the interactions between adults and young, concerning . The importance of these alimentary relationships, •r in passalids, is discussed. nutrition, has not been well elucidated yet. Apparently, the main source of food for Passalids is a mixture of powdered wood fragments produced Parental Behaviors, Subsocial Bchavior, Nutrition, during gallery excavation and faeces (Pearse et al, 1936; Gray, 1946; Reyes Castillo & Halffter, 1984; Valenzuela-González 1986a); these detritus are constantly compressed by adults against the gallery walls, which are usually ESUMEN Iined with this mixture. 111jo muestran que las larvas de los pusálidos son Ohaus (1900, 1909) was the first to propose that larvae depend on adults 1nadera. Su fuente principal de alimentación es una entos de madera producidos durante la excavación for their feeding, due an insufficient adaptation of their mandibules to )1 tampoco pueden sobrevivir con una dieta a base xylophagous nutrition. More recently, sorne studies have shown that adults tgerir, previamente, excrementos de otros adultos. have a mandibular force that is far superior to that of the larvae (Reyes elaciones simbióticas con microorganismos para la Castillo & Jarman, 1981; Jarman & Reyes-Castillo, 1985), a fact which Se encontró también que los excrementos de los could give sorne support to Ohaus's ideas. However, Heymons (1929) rontenido de nitrógeno que la madera de que se reported that the larvae's mandibules were well-adapted for this regime, and n los excrementos de las larvas, pero con menor dichos incrementos son considerablemente mayores he claimed that, concerning their feeding, larvae were independent from 1 larvas. Estas diferencias entre larvas y adultos, adults. Pearse et al (1936) and Gray (1946) made sorne additional ovechar la madera cpmo fuente de alimentación, observations, but their results are inconclusive concerning the participation II'Íaciones existentes en sus tubos digestivos. La of adults in larvae nutrition. Finally, Burnett et al, (1969) and Mason & 1 una estructura, que probablemente funciona corno Odum (1969) showed the importance of coprophagy in adults nutrition. ) de los adultos; dicha estructura no existe en las ~tos de la importancia que la xilofagia puede haber IOCial en estos insectos. Concerning the participation of symbiotic microorganisms iri the nutrition ofthese insects, Lewis (1926) and Pearse et al (1936) looked, unsuccesfully, ra, Comportamientos Parentales, Comportamiento for cellulotic protozoires in the gut of Odontotaenius disjunctus (Illiger). However, it is well known that bacterians and fungi are very. common in the intestines of Passalids, but it is unknown if they could have a significant participation in the nutrition of these insects (Lewis, 1926; Heymons & Heymons, 1934; Patterson, 1937; Lichtward 1957 & 1968; Baker, 1968). J 28 FOLIA ENTOMOL. MEX. 85 (1992) V ALENZUELA: ALIMENTARY R In this P.aper 1 pr~ent results which show that Iarvae and young adults can~ot survive on a diet made exclusive! y of wood; furthermore, 1 illustrate In order to determine if Iarvae car the Importance of the ingestion of adult faeces for both larvae and adults. of wood, the following experiment wa Passalus punctiger Lepeletier et Servil METHODOLOGY ANO R.ESUL TS In the first (n= 18), the Iarvae were · (n= 19), larvae were also fed on woo In order to evaluate the preferences of larvae when allowed to choose of fine sawdust in order that the larv: between different kinds of food, the following selection tests were made: in of using this group was to determine i1 glass Petri dishes 10 cm in diameter, equal amounts of the materials being a feeding dependance on the adults, tested were placed, symmetrically, in both sides of said dishes · then one suggested by Ohaus (1900, 1909). 11 first