Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
1. in-sĕco, cŭi, ctum, 1, v. a., to cut into, cut up (class.): aliquid dentibus, Auct. Her. 4, 49, 62: olivam acuta harundine, Col. 12, 47: corpora mortuorum ad scrutandos morbos, to dissect, Plin. 19, 5, 26, § 86: insecandi sunt favi, Col. 9, 15, 9: quod (subtemen) insecti pectine dentes, cut in, notched, Ov. M. 6, 58.
Hence, insectum, i, n. (sc. animale), an insect; plur., Plin. 11, 1, 1, § 1; 11, 28, 33, § 96 al.
2. insĕco or insĕquo, insexi, old form for insĕquor, to pursue the narration, to proceed, relate, declare; so imper.: insece, Musa, Enn. ap. Gell. 18, 9, 3 (Ann. v. 332 Vahl.): virum mihi, Camena, insece versutum, Liv. Andr. ap. Gell. 18, 9, 5; perf. subj.: insexit, dixerit, Enn. ap. Paul. ex Fest. p. 111 Müll.; gerund.: insecenda, Cato ap. Gell. 1. 1.