Corresponding author: Donald M. Windsor (
Academic editor: Michael Schmitt
A summary of literature, documented observations and field studies finds evidence that mothers actively defend offspring in at least eight species and three genera of Neotropical Chrysomelinae associated with two host plant families. Reports on three
Arthropod parents influence the survival prospects of offspring in a multitude of ways. When parents bring resources to larvae, guide larvae to resources or actively shield offspring from predators and parasitoids, they are engaging in subsocial behavior (
The
Below we review evidence of restricted host plant use and the presence of defensive maternal behavior in eight species of Neotropical
Tissue samples are preserved in ethanol at -80° C, and pinned adult voucher specimens are stored in the working collections of D.W., both at the Smithsonian Tropical Research Institute, Tupper Research and Conference Center, Panama City, Panama. Field observations reported below come from field notes and photographic records made at diverse occasions in Central and South America over the past 20 years.
Adult
Forward and Reverse sequences were combined and reconciled in Sequencher v5 (Gene Codes Corporation, Ann Arbor, MI, USA) and trimmed, leaving a single 472 bp fragment, which was then translated to amino acids and found free of stop codons. Sequences from ten species were combined with three sequences from GenBank creating an ingroup of 12 species (20 individuals) and a single outgroup species. Where possible we included two separate individuals from the same population. New sequences were deposited in GenBank under accession numbers in
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Gamboa, Panama Province, Panama | Apo | aggregated | yes | oviparous | - | new observation | ||
Boqueirão Reserve, Minas Gerais State, Brazil | Apo | aggregated | yes | oviparous | - | new observation | ||
El Porvenir, Meta Province, Colombia | Apo | aggregated | no | oviparous | - |
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Serra do Japi, Jundiaí, São Paulo State, Brazil | Sol | aggregated | no | larviparous | - |
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Yasuní, Orellana Province, Ecuador | Sol | ? | ? | ? |
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new observation | ||
Serra do Japi, Jundiaí, São Paulo State, Brazil | Sol | aggregated | no | larviparous |
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Montagne de Kaw, Roura Commune, French Guiana | Sol | solitary | no | larviparous | new observation | |||
Serra do Japi, Jundiaí, São Paulo State, Brazil | Sol | aggregated |
no | larviparous | - | |||
Ijuí, Rio Grande do Sul State, Brazil | Sol |
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aggregated | no | larviparous | - |
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Cerro Campana, Panama Province | Sol | aggregated | yes | larviparous |
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new observation | ||
Serra do Japi, Jundiaí, São Paulo State, Brazil | Sol | aggregated | no | larviparous |
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Serra do Japi, Jundiaí, São Paulo State, Brazil | Sol |
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aggregated | no | larviparous | - | ||
Serra do Japi, Jundiaí, São Paulo State, Brazil | Sol | aggregated |
no | larviparous | - | |||
La Selva Biological Station, Heredia Province, Costa Rica | Sol | aggregated | yes | larviparous | - |
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Serra de Baturite, Fortaleza, Brazil | Sol | solitary | no | larviparous |
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Ijuí, Rio Grande do Sul State, Brazil | Sol | aggregated | no | larviparous | - |
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Reventador, Napo Province, Ecuador | Sol | ? | ? | ? | new observation | |||
Yanayacu Biological Station, Napo Province, Ecuador | Sol | aggregated | yes | larviparous | new observation | |||
Serra do Japi, Jundiaí, São Paulo State, Brazil | Sol | aggregated | no | larviparous | - | |||
Reventador, Napo Province, Ecuador | Sol | ? | ? | ? | new observation | |||
Yasuní, Orellana Province, Ecuador | Sol | aggregated | yes | larviparous | new observation | |||
Río Malo & Reventador, Napo Province, Ecuador | Sol | aggregated | yes | larviparous | new observation | |||
Montagne de Kaw, Roura Commune, French Guiana | Sol | aggregated | yes | larviparous | new observation | |||
Cerro Campana, Panama Province, Panama | Mal | aggregated | no | oviparous |
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new observation |
1 Apo=
2=nocturnally active
3=larvae cut and cover themselves with trichomes
According to
Maternal care providing
Subsequently, individual
Larval emergence began on days 6 and 7 following first oviposition with clutches (n=3) at that time containing from 40–50 eggs. Within 24 hours after larvae began to emerge many of the original eggs were missing, apparently consumed by early-emerging larvae such that clutches were reduced to 8, 15 and 20 surviving larvae accompanied by some intact, opaque, less-developed eggs and opened eggs with red-colored residues of once-developing larvae visible under close inspection (
Once the natal leaf was consumed, larvae began moving down the petiole to the stem, where they then moved either up or down in smaller groups to other leaves, sometimes moving as solitary individuals. Mothers, often fed from the pedicel of the leaf just consumed, occasionally accompanied by one or two larvae. Mothers actively trampled upon the backs of larvae still located on the pedicel, in effect pushing them away from the leaf and toward the stem. Mothers on other occasions stepped on and over larvae, rapidly tapping larvae with antennae and tarsi until they reversed direction. After leaving the natal leaf, mothers resumed guarding one of the several larval groups that reassembled. However, some groups continued to split into ever smaller units and moved to adjoining leaves and stems, leaving mothers guarding smaller sets of offspring and spending more time travelling among groups in what seemed to the observer as an effort to herd offspring back together (
Recent observations by F.F. reveal clearly that maternal care is expressed by
Within New World
Maternal care providing
Female
Maternal care providing
The 17 larvae belonging to another female were observed to take approximately 30 hours to consume the entire lamina of the natal leaf. While the last of the leaf was being consumed some larvae began to molt while still on the remnants of the natal leaf. The mother maintained a tight grip on the leaf petiole (blocking behavior), but eventually larvae pushed by and began traversing nearby stem and petioles solitarily or in small groups. Commonly families split into two or more separated feeding groups at this stage, with the mother usually remaining with a larger group. Groups often reunited but others remained separated until pupation. The transition from the natal to second leaf appears to be a crucial and dynamic time for larvae and events proceeded differently for most groups. During this period mothers moved actively among different leaves and branches in what seemed to be attempts to herd and reconstitute a single larval group. While we observed what we interpret as herding behavior in most species in this report, its possible importance to group safety and success remains open and in need of experimental study.
Strong indications of maternal care in
Observations of
Two additional
Other
Two lines of evidence support the validity of the
Bayesian Consensus tree of 472 bp COI sequences obtained for 12 species of Central and South American
Aspects of the biology of 20 Neotropical species of
Because of the caveats to which mitochondrial data are subject (
New records of maternal care in New World
As
The second pattern beginning to emerge concerns choice of food plants. New World
We note that all eight maternal care species in the New World occur in distinctly tropical latitudes whereas subsocial
Maternal care behavior appears limited to three genera of Neotropical
We thank A. Valderama and E. Medianero (Universidad de Panamá) who provided key observations leading to the discovery of
1 Contribution to the 8th International Symposium on the